Valve-tappet construction



July 3, 1928. l.675,954

' C. H. PAGE VALVE TAPPET CONSTRUCTION Filed Aug. 26, 1924 Patented duly 19 28.

UNl'l-ED STATES.

PATENT "OFFICE.

CHARLES H. PAGE, OF CHARLOTTESVILLE, VIRGINIA, ASSIGNOR OI ONE-THIRD TO 14. G. EOX'ION AND ONE-THIRD T0 J. H. RYALLS, BOTH OF CHABLOTTFBVILLE, VIR- GINIA.

VALVE-TAPPET CONSTRUCTION.

Application filed August 26, 1924. Serial No. 734,258.

This invention relates to improvements in tappet constructions for internal combustion engine valves.

An object of the invention resides in providing a tappet construction for valves of internal combustion engines wherein means is associated with the tappet andrelatively movable with respect to the body portion thereof for engaging the end of the valve stem and resiliently supported by the body portion of the tappet adapted to eliminate the usual noise in valve tappet constructions as now experienced in the art.

Another object of the invention resides in providing a tappet construction for internal combustion engine valves including a body member formed with an axial bore in the upper end thereof of substantially large size and a smaller axial bore in the central por-v tion thereof communicating with said larger bore, and adapted to receive a plunger for sliding movement in said bore having an enlarged cylindrical portion provided with an annular flange on the upper end thereof adapted to slidably fit in the upper end of the enlarged bore of said body, and a reduced cylindrical projection slidably fitting within the smaller bore of the body, a coil spring being interposed between the lower end of the larger cylindrical portion and the end of the larger bore in said body for normally retaining the plunger in a partially projected position from the body for engagement in the lower end of thevalve stem, so that in the operation of the tappet, the body portion will be moved upwardly and the engagement with the valve stem cushioned by the spring and air chambers within the body for eliminating the usual noise between the tappets and valve, said structure providing for a centering of the plungerin the body portion of the tappet and the guiding thereof in axial alignment with respect to said body portion so that the pressure for raising the valve stem will be exerted in axial,a-lignment therewith.

The invention also includes other objects and improvements in the details of construction and arrangement of the parts which are more particularly pointed out in the following description and claims directed to a preferred form of the invention, it being understood, however, that various changes in the minor details and manner of assembling the is formed with the usual intakeor exhaust in a well known manner, for normally holding said valve in closed position. The usual cam shaft is indicated at 7, which is provided with the valve operating cam 8, while the tappet construction forming the subject matter of this invention is indicated generall at- 9.

his tappet construction includes a body portion 10 which is formed with a head 11 at the lower end thereof adapted to ride on and engage-the cam 8 for operation thereby in effecting the opening oi the valve 3. The upper end of the body portion 10 is formed with' an enlarged bore 12, extending axially from the upper end portion and terminating in the central portion of said body. A smaller bore 13 formed in the central portion of the body 10 is arranged in axial relation with the bore 12, and communicates therewith at the inner end. A plunger 14 comprises a cylindrical member adapted to slidably fit in the bore 12, and formed at the up er end in an annular radiallyextending flange 15, beyond the end of the body 10, and the lower end with a substantially long depending cylindrical projection 16 of a size to slidably fit in the small bore 13 in the central portion of the body. A coil spring 17 ismounted in the bore 12 around the extension 16 and engages the lower end of the plunger 14 and the lower end of the large bore 12 of the body, for normally forcing the plunger 14 outwardly, with respect to the body, so that the upper end thereof will engage the lower end of the valve stem 4, in a manner as illustrated in the drawing.

From this construction, it will be seen that in the operation of an engine, so equipped, that the plunger 14 will be constantly held by the spring 17, in engagement with the end of the valve stem. 4, the tension on the s ring not being sufiicient to overcome the cosing action of the spring 6, while the body 10 reciprocat'es due to the action of the cam 8 and the spring 17 forcing the same downwardly. In each upward movement of the body 10, it will be seen that a movement of the bod relative to the plunger is effected before tl ie body begins the lifting of the valve 3 through engagement of the lower end of the plunger 14 with the body of the small bore 13 in the body, the action of which is cushioned by the air contained in the small bore and the action of the spring 17, so that substantially all noise is eliminated by the cooperation of the plunger 14 and the body 10, in the operation of the valve 3. It is to be further noted that the provision of the enlarged bore 12 and the small bore 13 at "opposite ends of the spring 17 for receiving and slidably mounting the enlarged diameter of the plunger 14 in the bore 12 and the small cylindrical extension 16 therefrom provides a double bearing point for the lunger at the opposite ends thereof, in order that the plunger will be effectively guided in axial relation in the body, in the operation of the improved tappet construction, in order that a direct lifting force is applied to the valve in axial alignment with the stem 4.

What is claimed is: A tappet construction for internal combustion engine valves comprising a body portion formed with an enlarged bore openmg through one end portion thereof, and a smaller concentric bore in the central portion thereof communicating with said large bore and axially aligned therewith, a plunger slidably mounted in the larger bore and projecting beyond the end of said body por tion for engagement with the valve stem of said engine, said plunger having a reduced cylindrical extension extending through said larger bore and slidably fitting in the smaller bore, and resilient means interposed between the end of said plunger and the end of said larger bore in said body portion, the slidable mounting of the plunger providing bearings at spaced points adjacent the ends and beyond the ends of said resilient means for maintaining the axial sliding movement of the plunger in the bores, said small bore normally having a pocket beyond the end of said reduced extension providing a cushioning chamber for said plunger.

In testimony whereof I afiix my signature.

CHARLES H. PAGE,

formed 

